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.Dd November 14, 2012
.Dt PEELOFF 2
.Os Darwin
.Sh NAME
.Nm peeloff
.Nd extracts an association from a socket
.Sh SYNOPSIS
.Fd #include <sys/socket.h>
.Ft int
.Fo peeloff
.Fa "int socket"
.Fa "associd_t associd"
.Fc
.Sh DESCRIPTION
The parameter
.Fa socket
is a socket.  The communication domain of the socket determines the
availability and behavior of
.Fn peeloff .
In general,
.Fn peeloff
attempts to extract the association specified by
.Fa associd
into its own separate socket.
.Pp
The parameter
.Fa associd
specifies the association identifier.  It may be set to
.Dv ASSOCID_ANY
when there is only one association present; or one of the identifiers
returned from
.Xr getassocids 3 .
.Sh RETURN VALUES
The
.Fn peeloff
function returns -1 on error and the global variable
.Va errno
is set to indicate the error.  If it succeeds, it returns a non-negative
integer that is a descriptor for the extracted association.
.Sh ERRORS
The
.Fn peeloff
system call succeeds unless:
.Bl -tag -width Er
.\" ===========
.It Bq Er EBADF
.Fa Socket
is not a valid descriptor.
.\" ===========
.It Bq Er EINVAL
The
.Fa associd
argument is invalid; cannot be extracted; or the underlying protocol
is no longer attached to
.Fa socket .
.\" ===========
.It Bq Er ENOTSOCK
.Fa Socket
is a file, not a socket.
.El
.Sh SEE ALSO
.Xr connectx 2 ,
.Xr disconnectx 2 ,
.Xr socket 2 ,
.Xr getassocids 3 ,
.Xr getconnids 3 ,
.Xr getconninfo 3 ,
.Xr compat 5
.Sh HISTORY
The
.Fn peeloff
function call appeared in Darwin 13.0.0
